STAR Flow, Chirality and Vorticity PWG

["Wang, Fuqiang" <fqwang AT purdue.edu>]

Hi Jagbir,

Your results are quite interesting. I have a few further questions about the 
details of your analysis:
1. For each event you have Dbmax with the condition of |Dbasy|<0.25. You bin 
events of each centrality in Dbmax. You use all events in your analysis (i.e. 
you're not throwing away events based on Dbmax or Dbasy), right?
2. In your calculation of gamma=<...>/v2c for a particular Dbmax bin of a 
given centrality, the v2c is calculated using those events only, right?
3. For the charge reshuffle, you reshuffle the charges of all events, and 
repeat your analysis from step 1 (i.e. you treat this as a completely 
separate "new" data sample), right? Did you "randomize" the charges according 
to the positive/negative charge ratio of the given event? On s11, the 
Dbmax_shuffle distribution is a bit wider than the real distribution, do you 
understand why? How do you bin the Dbmax and Dbmax_shuffle into 10 bins, 
respectively (same bin edges or same fractions)?
4. Your correlated background gamma is calculated for the Dbmax bin where 
Dbmax is from the charge-shuffled events, but using restored charges, right? 
If so, then you're effectively taking gamma difference between Dbmax_i events 
and Dbmax_shuffle_i events (which are different events), right? Of course 
you've also removed the large charge-shuffle background which is basically an 
autocorrelation effect (sort to speak) due to the Dbmax (and Dbmax_shuffle) 
selection bias.
5. You divide Dbmax (and Dbmax_shuffle) into 10 bins and do your analysis in 
each bin separately, and then take the weighted average for your f_cme 
result. You could just use a single wide Dbmax (and Dbmax_shuffle) bin, then 
in principle you should get zero signal because the correlated "background" 
is your real signal since they are now identical event sample. So is your 
finite signal really due to the difference between the average of ratios and 
the ratio of averages (or perhaps also due to residual effect from shuffling)?

This is a complicated analysis. It would be really good to have more 
discussions so the details can flesh out better. 

Thanks,
Fuqiang



> -----Original Message-----
> From: Star-fcv-l <star-fcv-l-bounces AT lists.bnl.gov> On Behalf Of jagbir via 
> Star-
> fcv-l
> Sent: Tuesday, November 17, 2020 10:49 AM
> To: ShinIchi Esumi <esumi.shinichi.gn AT u.tsukuba.ac.jp>; STAR Flow, Chirality
> and Vorticity PWG <star-fcv-l AT lists.bnl.gov>
> Subject: Re: [Star-fcv-l] FCV PWG meeting, 18/Nov/2020 (Wed) 9:30am (New
> York time zone)
> 
> Dear ShinIchi, Prithwish and Jiangyong,
> 
> I would like to give "Update on event by event charge separation in
> Au+Au collisions at 200GeV with STAR detector"
> 
> Please add me to agenda.
> I will post my slides later.
> 
> Thankyou,
> Jagbir Singh
> 
> On 2020-11-16 15:57, ShinIchi Esumi via Star-fcv-l wrote:
> > Dear FCV PWG colleagues
> > We will have our weekly FCV PWG meeting on coming Wednesday
> > 18/Nov/2020
> > 9:30AM (in BNL) at our usual time and place. So if you have anything
> > to present, please let us know and please post your slide by Tuesday.
> > We'll talk about the "HLT express productions" in the beginning of the
> > meeting as you see in the agenda page. Jiangyong, please send a link
> > to your slide from last week.
> >
> > The zoom room link, ID and password are in our usual drupal agenda
> > page below.
> > Please also keep in mind that all the preliminary plots should have
> > already been there in the summary area below.
> > Best regards, Jiangyong, Prithwish and ShinIchi
> >
> > Meeting agenda page with zoom link :
> > https://drupal.star.bnl.gov/STAR/blog/jjiastar/bulkcorr
> >
> > Preliminary page :
> > https://drupal.star.bnl.gov/STAR/pwg/bulk-correlations/bulkcorr-prelim
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